Cutting elements with re-processed thermally stable polycrystalline diamond cutting layers, bits incorporating the same, and methods of making the same

ABSTRACT

A method of re-processing used TSP material layers to form cutting elements, bits with such cutting elements mounted on their bodies, and bits having re-processed TSP material layers attached to their bodies, as well as such cutting elements and bits are provided. The method includes providing a used TSP material cutting element having a TSP material layer and substrate, or a bit having a TSP material layer attached to the bit, removing the used TSP material layer from the cutting element or bit, cutting the used TSP material layer to a new shape, if necessary, optionally re-leaching the used TSP layer and re-using the TSP material layer to form a cutting element, or in forming a bit body. The formed cutting element may be mounted on a bit body.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority to and the benefit of U.S.Provisional Application No. 61/176,068, filed May 6, 2009, thedisclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

This invention is directed to a method of re-processing thermally stablepolycrystalline diamond (“TSP”) materials to form new cutting elementsand bits incorporating such cutting elements, as well as to such cuttingelements and bits.

A TSP material is typically formed by “leaching” at least a substantialportion of a catalyst from polycrystalline diamond (“PCD”) using aleaching agent. When formed, polycrystalline diamond comprisesindividual diamond crystals that are interconnected defining a diamondnetwork. A catalyst, which is used to facilitate the bonding of diamondcrystals to form the PCD is often found within the interstitial spacesin the diamond network. Catalyst used in the formation of PCD includemetals from the Group VIII of the Periodic Table, with cobalt being themost common. Cobalt has a significantly different coefficient of thermalexpansion as compared to diamond, and as such, upon frictional heatingof the polycrystalline diamond during use, the catalyst expands, causingcracking to form in the network structure, resulting in thedeterioration of the polycrystalline diamond layer. Polycrystallinediamond having a second phase metal catalyst will generally not havethermal stability at temperatures above 700° C. By removing, i.e., byleaching, the catalyst (e.g., the cobalt) from the diamond networkstructure, the polycrystalline diamond layer becomes more heatresistant, as well as less prone to cracking when heated. Typically,strong acids are used to “leach” the catalyst from the diamond networkstructure.

Generally, to form a PCD layer, a substrate of cemented tungsten carbide(a substrate where tungsten carbide particles are cemented together witha binder such as cobalt) is placed adjacent to a layer of diamondparticles, which may also be premixed with a catalyst, such as cobalt,in a refractory metal enclosure typically referred to as a “can”, as forexample a niobium can, and the combination is subjected to a hightemperature at a high pressure where diamond is thermodynamicallystable. This process is referred to as a high-temperature-high-pressuresintering process (an “HTHP sintering process”). This process results inthe recrystallization and formation of a polycrystalline diamond ultrahard material layer bonded on the tungsten carbide substrate. During theHTHP sintering process the catalyst helps form the bonds between thediamond particles forming the PCD. The PCD layer is then removed fromthe substrate by cutting off and by lapping off the substrate, asnecessary. The removed PCD layer is then leached to substantially removeall of the catalyst to form the TSP material. Typically at least 95%,and in many cases over 99% of the catalyst is removed such thatessentially a matrix of diamond bonded crystals, with no catalyst ormere traces of the catalyst, remain. In this regard the spaces occupiedby the removed catalyst remain void. The TSP material layer may then beattached to another substrate by brazing, or by ahigh-temperature-high-pressure process (an “HTHP bonding process”) wherea cemented tungsten carbide substrate is provided adjacent the TSP layerand is heated at a sufficient temperature and at a sufficient pressureto melt and get a binder, such as the cobalt in the tungsten carbide, toinfiltrate the void spaces in the TSP material layer for attaching theTSP material to the substrate forming a TSP material cutting element,such as a TSP material cutter or compact. Moreover, an infiltrant suchas a metal or metal alloy infiltrant, as for example copper, silver,copper alloys and silver alloys, which have a melting temperature thatis lower than the melting temperature of the diamond particles, may alsobe used to infiltrate the TSP material when being attached to thesubstrate. Infiltrants bond the TSP material to the substrate byinfiltrating the TSP material voids and are non-catalyzing. It should benoted that an HTHP bonding process is not a sintering process as is theHTHP sintering process referred in the formation on the PCD. Moreover,the times; temperatures and/or pressures in an HTHP bonding process maybe different than those in an HTHP sintering process. For conveniencethe term “HTHP process” is used herein to refer to a process requiringhigh temperature and high pressure as for example an HTHP sinteringprocess or on HTHP bonding process.

Currently, TSP material cutting elements and compacts are disregardedwhen a portion of their TSP layers wears by a pre-determined amountand/or the substrate on which they are attached on wears or erodes by apre-determined amount. As TSP material layers are relatively expensiveto manufacture, a way of re-processing and re-using such TSP materiallayers is desired.

SUMMARY OF THE INVENTION

In an exemplary embodiment a method of making a cutting element isprovided. The method includes removing a TSP material cutting elementfrom a bit. The TSP material cutting element includes a TSP materiallayer bonded to a substrate, where the TSP material layer is apolycrystalline diamond layer and where at least a substantial portionof a catalyst in at least a portion of such layer has been removed. Themethod further includes separating the TSP material layer from thesubstrate, and attaching the TSP material layer onto a new substrateforming a new cutting element. In another exemplary embodiment, themethod further includes leaching the TSP material layer to removesubstantially all of a catalyst and/or an infiltrant from the TSPmaterial layer prior to attaching. In another exemplary embodiment, atleast substantially all of the catalyst has been removed from the entireTSP material layer prior to attaching. In yet another exemplaryembodiment, the separated TSP material layer includes an infiltrant, andthe method further includes leaching the TSP material layer to remove atleast part of the infiltrant. In one exemplary embodiment, theinfiltrant is a metal or metal alloy infiltrant. In another exemplaryembodiment, attaching includes subjecting the TSP material layer portionand the new substrate to a HTHP bonding process using an infiltrant. Inyet a further exemplary embodiment, the infiltrant infiltrates only aportion of the TSP material layer during attaching. In yet anotherexemplary embodiment, the method also includes removing at least aportion of the infiltrant from the attached TSP material layer. Inanother exemplary embodiment, the method further includes cutting theTSP material layer leaving a cut TSP material layer portion, andattaching includes attaching the cut TSP material layer portion. In yeta further exemplary embodiment, the method further includes leaching theTSP material layer or the cut TSP material layer portion to remove atleast a portion of a catalyst and/or infiltrant in the TSP materiallayer or the cut TSP material layer portion. In one exemplaryembodiment, the new substrate is placed adjacent a side of the TSPmaterial layer, and another substrate is placed adjacent an oppositeside of the TSP material layer, whereby the TSP material layer issandwiched between the new substrate and the another substrate, and theTSP material layer and both substrates are subjected to a HTHP bondingprocess. In another exemplary embodiment, the another substrate is agreen powder including tungsten carbide. In yet another exemplaryembodiment, the new substrate and the powder together completelyencapsulate the TSP material layer. In a further exemplary embodiment,attaching is selected from the attaching methods consisting essentiallyof brazing and microwave sintering. In one exemplary embodiment, themethod further includes infiltrating at least a portion of the TSPmaterial layer with an infiltrant having a coefficient of thermalexpansion similar to the coefficient of thermal expansion of diamond.

In another exemplary embodiment, a method of making a cutting element isprovided. The method includes HTHP sintering a diamond material onto afirst substrate forming a polycrystalline diamond ultra hard materiallayer, including a catalyst, bonded onto the first substrate, separatingthe polycrystalline diamond ultra hard material layer from the firstsubstrate, removing at least a substantial portion of the catalyst fromat least a portion of the polycrystalline ultra hard material layerforming a TSP material layer, attaching the TSP material layer onto asecond substrate using a HTHP bonding process forming another cuttingelement. The method further includes mounting the cutting element to abit body, using the bit body with the cutting element to cut earthformations, removing the cutting element from the bit body, separatingthe TSP material layer from the second substrate, and attaching the TSPmaterial layer separated from the second substrate to a third substrateto form a new cutting element. In one exemplary embodiment, removing atleast a substantial portion of the catalyst occurs prior to separatingthe polycrystalline diamond layer from the first substrate. In anotherexemplary embodiment, the method further includes removing at least aportion of an infiltrant from the TSP material layer prior to, or after,attaching the TSP material layer separated from the second substrate tothe third substrate. In yet a further exemplary embodiment, the methodfurther includes determining whether an infiltrant has infiltrated theTSP material layer during attaching of the TSP material layer to thesecond substrate, and removing at least a portion of the infiltrant fromthe TSP material layer prior to, or after, attaching the TSP materiallayer separated from the second substrate to the third substrate. In oneexemplary embodiment, the infiltrant is a metal or metal alloyinfiltrant. In another exemplary embodiment, the method further includescutting the TSP material layer leaving a cut TSP material layer portion,and attaching the TSP material layer separated from the second substrateto a third substrate includes attaching the cut TSP material layerportion to the third substrate. In yet a further exemplary embodiment,an infiltrant infiltrates only a portion of the TSP material layer. Inanother exemplary embodiment, attaching the TSP material layer separatedfrom the second substrate to a third substrate includes subjecting theTSP material layer portion, and the third substrate to a HTHP bondingprocess using an infiltrant, such that the infiltrant infiltrates atleast a portion of the TSP material layer. In yet another exemplaryembodiment, the method further includes removing at least a portion ofthe infiltrant. In one exemplary embodiment, the third substrate isplaced adjacent a side of the TSP material layer, and another substrateis placed adjacent an opposite side of the TSP material layer, wherebythe TSP material layer is sandwiched between the third substrate and theanother substrate, and the TSP material layer and both substrates aresubjected to a HTHP bonding process. In another exemplary embodiment,the another substrate is a green powder including tungsten carbide. Inyet another exemplary embodiment, the new substrate and the powdertogether completely encapsulate the TSP material layer. In one exemplaryembodiment, the method further includes infiltrating at least a portionof the TSP material layer with an infiltrant having a coefficient ofthermal expansion similar to the coefficient of thermal expansion ofdiamond, and the infiltrating occurs after using the bit body.

In one exemplary embodiment, a method of forming a bit body is providedincluding receiving a used TSP material layer which is attached to asubstrate, which TSP material layer has been used to cut an object andwhere the TSP material layer is a polycrystalline diamond layer with atleast a substantial portion of a catalyst and/or infiltrant of at leasta portion of such layer has been removed. The method also requiresremoving the TSP material layer from the substrate, cutting the TSPmaterial layer into a plurality of TSP material layer pieces, providinga mold, providing a matrix powder, mixing the matrix powder with atleast one of the TSP material layer pieces, placing the mixed powderwith the at least one of the TSP material layer pieces in the mold,providing a binder material within the mold, and heating the mold toinfiltrate the mixed powder to form a bit body including a portionincluding the at least one of the TSP material layer pieces. In anotherexemplary embodiment, the method further includes removing the usedcutting element from a bit body. In yet another exemplary embodiment,the method further includes leaching the TSP material layer to remove atleast another portion of the catalyst or a portion of an infiltrant. Inyet a further exemplary embodiment, at least a substantial portion ofthe catalyst has been removed from the TSP material layer pieces. Themethod in one exemplary embodiment requires removing a worn portion ofthe TSP material layer. The used TSP material layer may be part of aused cutting element and may be attached to a substrate or may beattached to a used bit body. In such case, the used TSP material layeris removed from the substrate or bit body.

In a further exemplary embodiment, a method for forming a cuttingelement is provided including receiving a used TSP material layer, theTSP material layer having been used to cut an object, the TSP materiallayer being a polycrystalline diamond layer with at least a substantialportion of a catalyst in at least a portion of the layer having beenremoved. The claim also requires attaching the TSP material layer on asubstrate, and infiltrating the TSP material layer with an infiltrant.In yet a further exemplary embodiment, the method further includesremoving at least a substantial portion of the infiltrant from at leasta portion of the TSP material layer. In one exemplary embodiment, theinfiltrating occurs during attaching. In yet another exemplaryembodiment, the infiltrant is a material having a coefficient of thermalexpansion similar to the coefficient of thermal expansion of diamond. Inone exemplary embodiment, the method further includes cutting the TSPmaterial layer prior to attaching.

In another exemplary embodiment, a cutting element is provided. Thecutting element includes a substrate, and a TSP material cutting layerattached to the substrate, where the TSP cutting layer has beensubjected to at least two HTHP processes prior to being attached to thesubstrate, and where the TSP material layer is a polycrystalline diamondlayer with at least a substantial portion of a catalyst in at least aportion of such layer having been removed. In an exemplary embodiment,the at least a substantial portion of the catalyst has been removed fromthe entire polycrystalline diamond layer to form the TSP material layer.In one exemplary embodiment, the TSP material cutting layer has beensubjected to at least three HTHP processes prior to being attached. Inyet another exemplary embodiment, the TSP material cutting layerincludes a first region at least substantially free of an infiltrant anda second region including an infiltrant. In yet a further exemplaryembodiment, the infiltrant is the second region includes a materialhaving a coefficient of thermal expansion close to the coefficient ofthermal expansion of diamond. In yet another exemplary embodiment, a bitis provided including a body and any of the aforementioned cuttingelements mounted on its body.

In a further exemplary embodiment, a bit body is provided includingpieces of TSP material embedded in the body, the TSP material havingbeen subjected to at least two HTHP processes prior to being embedded,and where the TSP material is a polycrystalline diamond material with atleast a substantial portion of a catalyst in at least a portion of suchmaterial having been removed.

In another exemplary embodiment, a method of forming a cutting elementis provided. The method includes receiving a used cutting elementincluding a substrate and a TSP material layer attached to thesubstrate, wherein the TSP material layer is a polycrystalline diamondlayer with at least a substantial portion of a catalyst in at least aportion of such polycrystalline diamond layer having been removed,wherein a portion of at least one of the TSP material layer and thesubstrate is worn. The method further includes removing a section of theTSP material layer and a corresponding section of the substrateincluding the worn portion to form a new cutting element having at leastone of a new dimension and a new shape. In a further exemplaryembodiment, removing includes at least one of grinding, cutting andlapping of the TSP material layer and substrate. In one exemplaryembodiment, the method includes leaching the TSP material layer priorto, or after the removing, for removing substantially all of at leastone of a catalyst and an infiltrant from at least a portion of the TSPmaterial layer. In another exemplary embodiment, the method alsoincludes attaching the new cutting element to a bit body. In oneexemplary embodiment, removing a section of the TSP material layerexposes a new surface of the TSP material layer and the method furtherincludes removing at least one of a catalyst or an infiltrant for atleast a portion of the new surface.

In another exemplary embodiment, a method of forming a cutting elementis provided. The method includes receiving a used TSP material layerwhich been used to cut an object, wherein the TSP material layer is apolycrystalline diamond layer with at least a substantial portion of acatalyst in at least a portion of such polycrystalline diamond layerhaving been removed. The method further includes attaching the used TSPmaterial layer onto a substrate. In yet another exemplary embodiment,the method also includes leaching the used TSP material layer to removesubstantially all of the catalyst from the TSP material layer prior toattaching. In one exemplary embodiment, the attached used TSP materiallayer includes an infiltrant, and the method further includes leachingthe used TSP material layer to remove at least part of the infiltrant.In an exemplary embodiment, the infiltrant is an infiltrant selectedfrom the group of infiltrants consisting essentially of metalinfiltrants, and metal alloy infiltrants. In another exemplaryembodiment, bonding includes subjecting the used TSP material layerportion and the substrate to a HTHP bonding process using an infiltrant.The method may also include cutting the used TSP material layer leavinga cut used TSP material layer portion, and attaching includes attachingthe cut used TSP material layer portion. In one exemplary embodiment,the substrate is placed adjacent a side of the used TSP material layer,and another substrate is placed adjacent an opposite side of the usedTSP material layer, whereby the used TSP material layer is sandwichedbetween the substrate and the another substrate, and the used TSPmaterial layer and both substrates are subjected to a HTHP bondingprocess. In a further exemplary embodiment, the another substrate is agreen powder including tungsten carbide. In one embodiment, thesubstrate and the powder together completely encapsulate the used TSPmaterial layer. In yet a further exemplary embodiment, the method alsoincludes infiltrating at least a portion of the used TSP material layerwith an infiltrant having a coefficient of thermal expansion similar tothe coefficient of thermal expansion of diamond. In yet anotherexemplary embodiment, receiving includes receiving a cutting elementincluding a substrate bonded to the used TSP material layer, and themethod further includes removing the substrate from the used TSPmaterial layer. In yet a further exemplary embodiment, receivingincludes receiving a bit body having the used TSP material layerattached to the bit body, and the method further includes separating theused TSP material layer from the bit body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a used TSP material cutter having a TSPmaterial cutting layer.

FIGS. 2 and 3 are top views of the TSP material cutting layer of thecutter shown in FIG. 1 depicting possible cutting options in dashedlines.

FIG. 4 is a cross-sectional view of a bonding assembly including a can,a TSP material layer, a first substrate material and a second optionalsubstrate material which are to be HTHP bonded to form a cutting elementaccording to an exemplary embodiment of the present invention.

FIG. 5 is a perspective view of an exemplary embodiment TSP materialcutting element of the present invention.

FIG. 6 is a perspective view of an exemplary embodiment TSP materialcutting element of the present invention shown prior to machining toremove part of the substrate to expose the TSP material layer.

FIGS. 7A and 7B are perspective views of exemplary embodiment TSPmaterial cutting elements with only a portion of their TSP materialcutting layers being generally free of an infiltrant.

FIG. 8 is a plan view of an exemplary embodiment drag bit havingexemplary embodiment cutting elements of the present invention mountedthereon.

FIG. 9 is a schematically depicted cross-sectional view of a mold packedwith matrix material and TSP material pieces for forming the bit body ofthe bit shown in FIG. 8 in accordance with the present invention.

FIG. 10 is a schematically depicted cross-section view of an exemplaryembodiment bit body of the present invention.

FIG. 11 is perspective view of yet another exemplary embodiment drag bitof the present invention.

FIG. 12 is a cross-sectional view of an exemplary embodiment cuttingelement mounted on the bit body shown in FIG. 11 and taken along arrows12-12 through the bit body shown in FIG. 11.

FIGS. 13A, 13B, 13C, 13D, 13E, 13F, 13G and 13H are top views of TSPmaterial cutters depicting potential new shapes in accordance withexemplary embodiments of the present invention.

FIG. 13I is a perspective view of a new cutter having the potential newshape depicted in FIG. 13B.

FIG. 13J is cross-sectional view of a TSP material layer that has beenleached partially through its thickness having a worn portion.

FIG. 14 is flow chart of an exemplary process of the present inventionused to re-process TSP material.

DETAILED DESCRIPTION OF THE INVENTION

The present invention takes cutters, compacts, inserts, or bits whichinclude TSP material layers, such as TSP material cutting layers, whichhave been used in the field and re-processes their TSP material layersto form new TSP material cutting elements such as shear cutters,compacts, or inserts for mounting on a bit or cutting elements which areembedded in bit body surfaces, which cutting elements are used forcutting earth formations. It should be noted that a “cutting element” asused herein refers to any type of cutting structure including an ultrahard material layer such as a TSP material layer and may or may notinclude a substrate. For example, as TSP material layer by itself is a“cutting element” as is a shear cutter having a TSP material cuttinglayer attached to a substrate.

Typically, when TSP cutters, compacts, or inserts (collectively referredto herein as “cutters”) become dull, and/or when their substrates wearor erode, they are removed from a bit on which they are installed on andare replaced with new cutters. The used cutters are typically thrownaway. Applicants have discovered that they can successfully re-processthe TSP material from such cutters and believe that after re-processingsuch TSP material, the re-processed TSP material may even have betterproperties than originally. For example, in a case where a cutter 10(FIG. 1) is removed from bit because an edge 12 of a TSP layer 14 ofsuch cutter is dull, the TSP layer 14 may be separated from the cutterby removing the substrate 16 of the cutter, as for example cutting off alarge portion of the substrate and by lapping off the remaining portionof the substrate. The TSP layer may then be cut to an appropriate sizeor shape(s). For example, if the cutter was a 16 mm cutter (i.e., acutter having a 16 mm diameter), the TSP material layer may be cut, asfor example shown in FIG. 2 along dashed line 17, to a 13 mm diameterlayer 18 for forming a 13 mm cutter. The cut TSP material is thenleached to remove to remove substantially all the infiltrant and/orcatalyst from at least a portion of the cut TSP material. Alternatively,the cutter may be cut to remove the dull portion of the TSP materialalong with its corresponding substrate portion without separating theTSP material from the substrate. The remaining TSP material withattached substrate is then leached to remove to remove substantially allthe infiltrant and/or catalyst from at least a portion of the remainingTSP material.

In an exemplary embodiment, the TSP material may be cut into strips 19,by cutting the removed TSP layer as for example shown in FIG. 3 bydashed lines 20. The strips 19 may be used in cutters which incorporatestrips of TSP material, as for example the cutters disclosed in U.S.patent application Ser. No. 11/350,620, filed on Feb. 8, 2006, thecontents of which are fully incorporated herein by reference. Yet inanother exemplary embodiment, the used TSP material layer may be cutinto various other shapes, as for example, oval, semi-circular, square,rectangular, triangular, etc., and such shapes can be attached on newsubstrates to form new cutters such as those described in U.S. patentapplication Ser. No. 11/350,620, which requires only that sections of acutter cutting table (i.e., cutting layer) are formed from a TSPmaterial layer, and such as those described in U.S. patent applicationSer. No. 12/245,582, filed on Oct. 3, 2008, the contents of which arefully incorporated herein by reference. The cut TSP material layer maybe attached to the new substrate using an HTHP bonding process or othermethods such as microwave sintering or brazing. The cutting of the TSPmaterial layer may accomplished using known methods, as for exampleElectro-Discharge Machining (EDM), Electro-Discharge Grinding (EDG) orlaser cutting. Prior to attaching, the TSP material layer is leached toremove substantially all of the infiltrant and/or catalyst for at leasta portion of such layer so that such portion may be re-infiltratedduring the bonding process for re-attaching the TSP material layer tothe new substrate.

In other exemplary, embodiments, the used TSP material layer, e.g., theTSP material layer of a used cutter may be re-processed without cutting.For example, in a case when a cutter is not useable due to substratewear or erosion, the substrate of such cutter may be removed and the TSPmaterial layer of such cutter may be re-used to form new cutters withouthaving to be cut.

Once the used TSP material layer is removed from its substrate, in anexemplary embodiment, the removed TSP layer may be re-leached to removesome of the infiltrant, e.g. the cobalt, that may have re-infiltratedthe TSP material layer from the substrate when it was originallyattached to its substrate by an HTHP bonding process or an infiltrantthat may have been added to facilitate the bonding process, as forexample a metal or metal alloy infiltrant and/or any catalyst that mayhave been left over in the layer. Exemplary infiltrants include copper,silver, copper alloys and silver alloys, as well as other metal andmetal alloys whose coefficient of thermal expansion is similar to thatof diamond, as for example less than three times the coefficient ofthermal expansion of diamond. The TSP material layer may be then cut, ifnecessary to the appropriate shape or shapes. In some exemplaryembodiments the TSP material layer is cut to remove a worn portion ofthe TSP material layer. The cutting of the layer to the appropriateshape may be accomplished even prior to the re-leaching process. Forconvenience, whether cut or not, the TSP material layer removed from thesubstrate is referred to as the “reclaimed TSP material layer.” In caseswhere the reclaimed TSP material layer is used to form a cutting table,or part of a cutting table of a cutter, the reclaimed TSP layer may beattached to a new substrate to form a new cutting element or compactwith a “re-processed” TSP layer. The attaching may occur using microwavesintering or other known bonding methods, or can be HTHP bondingprocessed onto a new substrate by placing the reclaimed TSP layer 40adjacent a tungsten carbide substrate 42 in a refractory metal can 44,as for example shown in FIG. 4, and subjecting the assembly to a HTHPbonding process forming a cutting element 45 having a TSP cutting layer40 attached to a substrate 42, as for example shown in FIG. 5. Thesubstrate may be a cemented tungsten carbide substrate or may be inpowder of green form. In a further exemplary embodiment, a secondsubstrate material 46, such a green tungsten carbide powder may beincorporated to sandwich the reclaimed TSP layer between such substratematerial 46 and said substrate 42, as for example shown in FIG. 4. Inthe shown exemplary embodiment, the tungsten carbide powder, i.e.,substrate material 46, flows around the periphery of the reclaimed TSPmaterial layer forming a portion 47 surrounding the reclaimed TSPmaterial layer periphery, as for example shown in FIG. 6. This assemblyis then subjected to an HTHP bonding process forming a compact where thereclaimed TSP material layer is completely encapsulated by thesubstrates 42 and 46, as for example shown in FIG. 6. The substrate 46and part of the substrate 42 are then removed, as for example bylapping, to form the cutting element 45 with a re-processed TSP materiallayer 40 as shown in FIG. 5. In another exemplary embodiment, instead ofa green powder, the second substrate may be a cemented material, such ascemented tungsten carbide, a pre-cemented tungsten carbide powder, apre-sintered tungsten carbide powder, or tungsten carbide (WC—Co)powder. Pre-cemented tungsten carbide powder is formed by formingcemented tungsten carbide, as for example a cemented tungsten carbidesubstrate, and then crushing it to form the powder. Pre-sinteredtungsten carbide powder, is powder that has only been partiallysintered.

The re-processed TSP material layer may be tailored to have a firstregion free or substantially free of an infiltrant and a second regionhaving an infiltrant that infiltrated the TSP material layer during theHTHP bonding process. This can be accomplished by leaching to remove theinfiltrant from the first region. In an exemplary embodiment a firstregion 41 extends across the entire upper portion of the re-processedTSP material layer 40 as for example shown in FIG. 7A. In anotherexemplary embodiment, the first region 41 covers only an upper portionincluding the edge of the TSP material layer 40 that will be used to cutthrough the earth formations, as for example shown in FIG. 7B. The depthof the first region may be dependent on the type of earth formationsthat will be cut. For example, with earth formations that will generatehigher frictional heat on the TSP material layer, the first regionshould be deeper. Thus, the size of the first region of the TSP materialmay be defined by the type of cutting for which the TSP material layerwill be used. In this regard, by limiting the depth and/or size of thefirst region, the time required to leach the infiltrant is also limited,i.e., reduced. In an exemplary embodiment, when the re-processed TSPmaterial is fully infiltrated during the bonding process, at least aportion of such re-processed TSP material layer is leached to remove atleast a substantial portion of the infiltrant accompanying such portionof the re-processed TSP material layer. It should be understood that anyportion of a TSP material that is infiltrated with a metal or metalalloy infiltrant, e.g., cobalt, may no longer be a TSP material as itwould include the metal or metal alloy infiltrant, e.g. the cobalt.However, for descriptive purposes such portion is described herein asbeing an TSP material that has been infiltrated or re-infiltrated or are-processed TSP material or a TSP material that has been infiltrated orre-infiltrated.

In another exemplary embodiment, the reclaimed TSP material layer may becut into pieces 29 and incorporated into a bit making process where theTSP material layer pieces are mixed with a matrix material which is usedto form a portion of the bit body, as for example the outer surface 24,and/or the blades 26 of a drag bit 28 as for example shown in FIG. 8.The reclaimed TSP material are leached, as necessary, prior to or aftercutting, if cutting is necessary. Processes for forming bit bodieshaving outer surfaces incorporating ultra hard material, as for examplepolycrystalline diamond, ultra hard material particles, are described inU.S. patent application Ser. No. 11/250,097, filed on Oct. 12, 2005, thecontents of which are fully incorporated herein by reference.

In an exemplary embodiment, to form a bit body a mold 30 is provided, asfor example shown in FIG. 9. The mold is commonly formed of graphite andmay be machined into various suitable shapes. Displacements 31, as forexample plugs, are typically mounted in the mold to define pockets foraccommodating cutting elements such as cutters and for defining cavitiesto accommodate nozzles and the like. A matrix powder 32 that is used toform the outer surface or a portion of the outer surface of the bit bodyis placed in the mold. The matrix powder may be a powder of a singlematrix material such as tungsten carbide, or it may be a mixture of morethan one matrix material such as different forms of tungsten carbide.The matrix powder may include further components such as metaladditives. The reclaimed TSP material pieces (the “TSP pieces”) 29 areadded and mixed with the matrix powder 32 prior to the placing of thematrix powder in the mold. The same or a different matrix powder 33,with or without the TSP pieces is placed in the mold adjacent alreadyplaced matrix powder. Metallic binder material 34 is then typicallyplaced over the matrix powder. The components within the mold are thenheated in a furnace to the flow or infiltration temperature of thebinder material at which the melted binder material infiltrates thetungsten carbide or other matrix material. This heating process is aninfiltration process although it is also commonly referred to assintering or liquid phase sintering. This infiltration process bonds thegrains of matrix material to each other and to the other components toform a solid bit body that is relatively homogenous throughout. Thisinfiltration process also causes the matrix material to bond to otherstructures that it contacts as well, such as a metallic blank 36 whichmay be suspended within the mold to produce the aforementionedreinforcing member. The formed bit body is then removed from the moldwith the TSP pieces being embedded in the outer surface of the bit body.After formation of the bit body, a protruding section of the metallicblank may be welded to a second component 37 called an upper section(FIG. 8). The upper section typically has a tapered portion 38 that isthreaded onto a drilling string. In other exemplary embodiments, the TSPpieces maybe embedded in other portions of the bit body.

In one exemplary embodiment, the TSP pieces 29 may be positioned in themold to form cutting elements 29 protruding from the outer surface ofthe bit body 49, as for example shown in FIG. 10. With such an exemplaryembodiment, the TSP pieces are cut to have sufficient size for formingsuch cutting elements. The bit body 49 in one exemplary embodiment, maybe a bit body for a drag bit 28 as for example shown in FIG. 8 or may bea diamond impregnated bit, a roller cone bit or any other type of bit.These are well known bits in the art. Exemplary bits are disclosed inU.S. Patent Publication No. 2006/0032677, published on Feb. 16, 2006,the contents of which are fully incorporated herein by reference.

In other exemplary embodiment, reclaimed TSP material layers and/or TSPpieces may be positioned in a mold so as to form bit body cuttingelements or may be bonded to the bit body after the bit body is formedto form bit body cutting elements. For example the reclaimed TSP may beshaped, as necessary, and attached to the leading edges of the blades,e.g. blades 126, of the bit body 128 to form shear cutting elements, asfor example shown in FIGS. 11 and 12. The reclaimed TSP material layers40 or TSP pieces (29) may be bonded with out the use of a substrate, forexample by using metals, or other known methods, to a leading edge 126of a bit body 128 or may be positioned in the mold used for forming thebit body such that they are attached by infiltration by an infiltrant(e.g., cobalt and/or other metallic binder material used) to the bitbody when it is formed. In this regard the TSP material layers and/orTSP pieces form shearing cutting elements 150 attached to the bit body128. In an exemplary embodiment, a shearing cutting element 150 may besandwiched between a lip portion 152 and a backing portion 154 which ispart of the blade 126, as for example shown in FIG. 12. These reclaimedTSP material layers and/or pieces, may be re-leached as necessary toremove any infiltrant and/or any left over catalyst from at least aportion of the TSP layers or TSP pieces.

In other exemplary embodiments, reclaimed TSP material layers 40 and/orTSP pieces 29 may be embedded in the bit body by being attached to thebit body using known methods or by positioning such layers and/or pieceswithin the mold forming the bit body such that these layer or pieces areattached to the bit body when the bit body is formed to form cuttingelements, such as secondary cutting elements 160 positioned behind thecutting elements 45, as for example shown in FIG. 8. As can been seen,these reclaimed TSP material layers and TSP pieces may be attached tothe bit body without first being attached to a substrate.

In another exemplary embodiment, a used cutting element 80 whichincludes a TSP material layer 82 having a worn portion 84 and/or a wornor eroded substrate may be ground, cut and/or lapped (individually orcollectively referred to as “cut”) to remove a worn portion of the TSPmaterial layer along with its corresponding substrate and then reused(FIGS. 13A to 13G). For example, in one exemplary embodiment, a largerdiameter cutting element, as for example a 16 mm diameter shear cuttertype cutting element, i.e., a cutting element having 16 mm diameterhaving a worn TSP material layer portion may be ground, cut and/orlapped to a smaller diameter shear cutter type cutting element 86 (shownin dashed lines on FIG. 13A), as for example a 13 mm shear cutter typecutting element, by cutting the new diameter cutting element at alocation not including the worn portion 84 and removing the worn portionof the TSP material layer along with its corresponding substrateportion. The TSP material layer may be re-leached as necessary aftercutting to remove any infiltrant and/or any left over catalyst.

In other exemplary embodiments, instead of a circular cutting element,other shapes such as an elliptical shape 88 (FIG. 13B), an oblong shape90 having parallel sides (FIG. 13C) or an oblong shape 92 (FIG. 13D)having non-parallel sides, or a triangular shape 94 (FIG. 13E), or asemi-circular shape 96 (FIG. 13F), or a tombstone shape 98 (FIG. 13G),or multiple shapes 100 and 102 (FIG. 13H) may be cut from the usedcutting element to remove the worn portion 84 of the TSP material layer82 along with its corresponding substrate to form a reclaimed cuttingelement having such shape. These shapes have been provided by way ofexample, other shapes may also be cut. Once the worn portion of the TSPmaterial layer is removed, the newly defined TSP material layer willhave a newly exposed peripheral surface 89, as for example shown in FIG.13I. Such peripheral surface may still contain a catalyst and/or aninfiltrant. Consequently, such surface may also have to be leached toremove at least a substantial portion of the catalyst and/or infiltrantfrom such peripheral surface. It is preferable that all surfaces of theTSP material layer that make contact with the earthen formations duringcutting are substantially free of catalysts and/or infiltrants. In suchcase, the newly exposed peripheral surface 89 will have to be leached ifthe TSP material layer was not leached through its entire thicknessprior to be being cut to remove the worn portion. For example, as shownin FIG. 13J, section 83 of TSP material layer 82 was originally leachedsuch that TSP material layer 82 had a leached portion 83 substantiallyfree of a catalyst and/or an infiltrant and a non-leached portion 85.After the TSP material layer is cut along line 87 to remove worn portion84, the new peripheral surface (or peripheral surface section) 89exposed has a portion 91 which has not been leached. Thus, the newlyperipheral surface section 89 or at least its portion 91 will have to beleached in order to ensure that the entire new peripheral surfacesection 89 is substantially free of a catalyst and/or an infiltrant.

The TSP material layer may be re-leached, if necessary, to form adefined region on the cut TSP material layer that is free of catalystsand/or infiltrants. The re-leaching may occur prior to, or aftercutting. Removal of the catalyst infiltrant creates voids within the TSPmaterial layer in the space previously occupied by the infiltrant. Thereclaimed cutting element may then be attached to a bit body using knownmethods.

In other exemplary embodiments, TSP material cutter having a worn oreroded substrate portion and not necessarily a worn TSP material portionmay be cut in any shape to remove the worn or eroded substrate portionalong with its corresponding TSP material layer portion to foam a newreclaimed cutting element. In a further exemplary embodiment, a cuttingelement incorporating a TSP layer, which cutting element has not beenused but which is defective, may be cut to a new desired shape or asmaller similar or identical shape discarding the defective TSP layerportion and/or substrate to form a reclaimed new cutting element andre-leached, if necessary, as described above in relation to FIGS. 13A to13H. Such reclaimed cutting element may be used as a bearing, as forexample an insert for a thrust bearing ring, as for example described inU.S. Pat. No. 4,560,014, the contents of which are fully incorporatedherein by reference.

An exemplary process is shown in the algorithm depicted in FIG. 14.First a used TSP cutting element having a TSP material layer attached toa substrate is received from the field as depicted in field 50. Adecision is made on whether to remove the substrate from the TSPmaterial layer (field 53) by grinding, cutting and/or lapping. If thesubstrate is not removed, the cutting element is ground, cut and/orlapped to a smaller dimension and/or different shape so as to remove anyworn portion and to form a new cutting element (field 55). The TSPmaterial layer is then leached again for forming at least region atleast substantially free of infiltrant and/or a catalyst, as for exampledepicted in field 57. If the TSP material layer is separated from thesubstrate the reclaimed TSP material layer may be leached, as depictedin field 56. The new use of the reclaimed TSP material layer is thendetermined, as depicted in field 58. It should be understood, that thedecision on the new use of the TSP material layer can be made at anypoint in the process, even before the TSP cutting element is received,i.e., even before field 50. If the new use is to form cutting elementsfor embedding in a surface of bit, or for attaching to a bit, then thereclaimed TSP material layer may be cut, if necessary, to theappropriate shapes having the appropriates sizes, as for exampledepicted in field 60. The piece(s) cut or otherwise are then leached asnecessary to remove any infiltrant and/or a catalyst from at least aportion of the piece(s) (field 61) especially if leaching did not occurin field 56. The piece(s) are then mixed with a matrix material used toform the bit outer surface, or are attached to a formed bit, as forexample depicted in field 62. The piece(s) may be leached, if necessary(field 63). If a decision is made to use the reclaimed TSP materiallayer to form a cutting layer to be bonded to a substrate to form acutting element, such as a shear cutter for mounting a drag bit body, orto form an insert for mounting on bit body, such as a roller cone bit ora percussion bit, or for mounting on a thrust bearing, or a compact, thereclaimed TSP layers is cut to the appropriate size, if necessary, asfor example depicted in field 66. The cut TSP material layer is leached(field 67) to remove any infiltrant and/or a catalyst, especially if itwas not leached in field 56. The reclaimed TSP layer is then attached toa new substrate, as for example a tungsten carbide substrate, bybrazing, microwave sintering, HTHP bonding processing or other knownmethods, as for example depicted in field 68. The attached TSP materiallayer is then leached again, if necessary, for forming at least regionat least substantially free of infiltrant.

In other exemplary embodiments, the present invention re-processes TSPmaterial layers which have been attached on substrates to form acompacts or cutting elements which are defective, even though suchcompacts or cutting elements have not been used to cut. With thisexemplary embodiments, the TSP material layers are re-processed asdescribed above. In other exemplary embodiments, a TSP material layerthat is being re-processed is a TSP material layer that in not attachedto a substrate but which has been used for cutting. Such TSP materiallayer is cut, if necessary, and re-processed as described herein.

Applicants believe that the properties of the re-processed TSP layersimprove by being subjected to the additional HTHP bonding process forbonding the used TSP layer to the substrate. Applicant's also believethat in the embodiments, where a re-processed TSP layer is HTHP bondingprocessed adjacent to green tungsten carbide powder 46, as for exampledescribed with relation to FIG. 4, the re-processed TSP material layerwill have better resistance to any micro-cracking in such re-processedTSP layer.

Although the present invention has been described and illustrated inrespect to various exemplary embodiments, it is to be understood that itis not to be so limited, since changes and modifications may be madetherein which are within the full intended scope of the this inventionas hereinafter claimed. For example, the reclaimed TSP material layersdescribed herein may be used in all applications where PCD or TSPmaterial is currently being used in lieu of such PCD or TSP material andmay be shaped in any shape necessary by grounding, cutting and/orlapping. In addition, the TSP material may be reclaimed from bits, asfor example from bits where the TSP material layer is embedded in suchbit body or is otherwise attached to such bit body with or without asubstrate. In addition, with any of the aforementioned embodiment, theTSP material that is being reclaimed may be TSP material that hasalready been reclaimed at least once before. Moreover, any reclaimed TSPmaterial may be leached at any point to remove any infiltrant and/orresidual catalyst from at least a portion of the material. Furthermore,the infiltrants identified herein for infiltrating the TSP material havebeen identified by way of example. Other infiltrants may also be used toinfiltrate the TSP material and include metals and metal alloys such asGroup VIII and Group IB metals and metal alloys. It should be also notedthat when a ceramic material or an oxide is used as an infiltrant, suchmaterials cannot be typically leached using a leaching acid. Moreover,it should be understood that the TSP material that is being re-claimedmay have been attached to other carbide substrates besides tungstencarbide substrates, such as substrates made of carbides of W, Ti, Mo,Nb, V, Hf, Ta, and Cr and/or may be re-processed and attached to othersubstrates such as substrates made of carbides of W, Ti, Mo, Nb, V, Hf,Ta, and Cr. Moreover, leaching has been used herein by way of examplefor removing an infiltrant and/or a catalyst. Other methods that canserve the same purpose may also be used.

What is claimed is:
 1. A method of forming a cutting element comprising:receiving a used cutting element comprising a substrate and a thermallystable polycrystalline diamond (TSP) material layer attached to saidsubstrate, wherein said TSP material layer is a polycrystalline diamondlayer with at least a substantial portion of a catalyst in at least aportion of said polycrystalline diamond layer having been removed,wherein a portion of at least one of said TSP material layer and saidsubstrate is worn; removing a section of said TSP material layer and acorresponding section of said substrate including said worn portion toform a new cutting element having at least one of a new dimension and anew shape, wherein removing said section exposes a new surface of saidTSP material; and removing at least one of a catalyst and an infiltrantfrom at least a portion of said new surface.
 2. The method as recited inclaim 1 further comprising leaching said TSP material layer prior to, orafter said removing a section, for removing substantially all of atleast one of a catalyst and an infiltrant from at least a portion ofsaid TSP material layer other than said new surface.
 3. The method asrecited in claim 1 further comprising attaching said new cutting elementto a bit body.
 4. The method as recited in claim 1 wherein said newcutting element is an insert, the method further comprising using saidinsert or as a bearing insert on a thrust bearing.
 5. A method of makinga cutting element comprising: removing a thermally stablepolycrystalline diamond (TSP) material cutting element from a bit, saidTSP material cutting element comprising a TSP material layer bonded to asubstrate, wherein said TSP material layer is a polycrystalline diamondlayer wherein at least a portion of a catalyst in at least a portion ofsuch layer had been removed; separating said TSP material layer from thesubstrate; removing substantially all of at least one of a catalyst andan infiltrant from at least a portion of said TSP material layer; andattaching said TSP material layer onto a new substrate forming a newcutting element, wherein during attaching said TSP material layer is atleast partially infiltrated with an infiltrant becoming an infiltratedTSP material layer.
 6. The method as recited in claim 5 furthercomprising removing substantially all of said infiltrant from at least aportion of said infiltrated TSP material layer.
 7. The method as recitedin claim 5 further comprising removing substantially all of saidinfiltrant from at least a portion of said infiltrated TSP materiallayer only if said infiltrated TSP material layer is fully infiltrated.8. The method as recited in claim 5 wherein removing comprises leachingsaid infiltrated TSP material layer to remove substantially all of atleast one of the catalyst and said infiltrant from at least said portionof said infiltrated TSP material layer.
 9. The method as recited inclaim 5 wherein at least substantially all of the catalyst has beenremoved from said entire TSP material layer prior to attaching.
 10. Themethod as recited in claim 5 wherein the infiltrant is a metal or metalalloy infiltrant.
 11. The method as recited in claim 5 wherein attachingcomprises subjecting said TSP material layer and said new substrate to ahigh temperature high pressure (HTHP) bonding process using saidinfiltrant.
 12. The method as recited in claim 5 further comprisingcutting said TSP material layer leaving a cut TSP material layerportion, and wherein attaching comprises attaching said cut TSP materiallayer portion.
 13. The method as recited in claim 5 wherein said newsubstrate is placed adjacent a side of said TSP material layer, andwherein another substrate is placed adjacent an opposite side of saidTSP material layer, whereby said TSP material layer is sandwichedbetween said new substrate and said another substrate, and wherein theTSP material layer and both substrates are subjected to a HTHP bondingprocess.
 14. The method as recited in claim 13 wherein said anothersubstrate is a green powder comprising tungsten carbide.
 15. The methodas recited in claim 13 wherein said new substrate and said powdertogether completely encapsulate said TSP material layer.
 16. The methodas recited in claim 5 wherein said attaching is selected from theattaching methods consisting essentially of brazing and microwavesintering.
 17. The method as recited in claim 5 further comprisinginfiltrating at least a portion of said TSP material layer with aninfiltrant having a coefficient of thermal expansion similar to thecoefficient of thermal expansion of diamond.
 18. The method as recitedin claim 5 further comprising cutting said TSP material layer leaving acut TSP material layer portion.
 19. The method as recited in claim 5further comprising: prior to removing, HTHP sintering a diamond materialonto a first substrate forming a polycrystalline diamond ultra hardmaterial layer including a catalyst, bonded onto said first substrateforming said cutting element; separating said polycrystalline diamondultra hard material layer from said first substrate; and removing atleast a substantial portion of the catalyst from at least a portion ofsaid polycrystalline ultra hard material layer forming said TSP materiallayer.
 20. The method as recited in claim 19 wherein removing at least asubstantial portion of the catalyst occurs prior to separating saidpolycrystalline diamond layer from said first substrate.
 21. A method offorming a bit body comprising: receiving a used thermally stablepolycrystalline diamond (TSP) material layer said TSP material layerhaving been used to cut an object; cutting said used TSP material layerinto a plurality of TSP material layer pieces; providing a mold;providing a matrix powder; mixing said matrix powder with at least oneof said TSP material layer pieces; placing said mixed powder with saidat least one of said TSP material layer pieces in said mold; providing abinder material within said mold; and heating said mold to infiltratesaid mixed powder and said TSP material layer pieces with said binder toform a bit body comprising a portion including said at least one of saidTSP material layer pieces.
 22. The method as recited in claim 21 furthercomprising leaching said TSP material layer to remove at least one of aportion of a catalyst and a portion of an infiltrant.
 23. The method asrecited in claim 21 wherein at least a substantially portion of thecatalyst has been removed from the TSP material layer pieces.
 24. Themethod as recited in claim 21 wherein said cutting comprises removing aworn portion from said TSP material layer.
 25. The method as recited inclaim 21 wherein receiving comprises receiving a used cutting elementcomprising a substrate bonded to said used TSP material layer, andwherein the method further comprises removing said substrate from saidTSP material layer.
 26. The method as recited in claim 25 furthercomprising removing said used cutting element from a bit body.
 27. Themethod as recited in claim 25 wherein receiving comprises receiving aused bit body having said TSP material layer attached to said bit body,and wherein the method further comprises separating said TSP materiallayer from said bit body.
 28. A method for forming a cutting elementcomprising: receiving a used thermally stable polycrystalline diamond(TSP) material layer, said TSP material layer having been used to cut anobject, said TSP material layer being a polycrystalline diamond layerwith at least a substantial portion of a catalyst in at least a portionof said layer having been removed; attaching said TSP material layer ona substrate; and infiltrating said TSP material layer with aninfiltrant.
 29. The method as recited in claim 28 further comprisingremoving at least a substantial portion of said infiltrant from at leasta portion of said infiltrated TSP material layer.
 30. The method asrecited in claim 28 wherein said infiltrating occurs during attaching.31. The method as recited in claim 28 wherein said infiltrant is amaterial having a coefficient of thermal expansion similar to thecoefficient of thermal expansion of diamond.
 32. The method as recitedin claim 28 further comprising cutting said TSP material layer prior toattaching.